2l8 



MARKETABLE BRITISH MARINE FISHES 



In the Irish Survey a number of the earHer transformation 

 stages of flat-fishes were taken in tow-nets attached to the trawl- 

 beam in Donegal Bay, at 30 to 32 fathoms, on the 14th and iSth 

 of May. Mr. Holt^ attributes these to the long rough dab, but 

 distinguishes two scries — one of longer specimens, one of shorter. 

 From the excellent figures which he has published I have no 

 doubt myself that the longer specimens were young plaice, and 

 the smaller were dabs. There is a very close resemblance 

 between the figures given by Mr. Holt, and that which is 

 reproduced in Fig. 107. 



Later stages, from that shown in Fig. 107 to the fully de- 

 veloped little plaice, were also taken during the Irish Survey, at 



Fig. 107. — Larva of Plaice in process of transformation, f inch long, alive, 

 and macrnified. 



depths of I to 32 fathoms, in May 1892. They ranged in size from 

 10 to 21 mm. (f inch to nearly i inch). The oldest, completely 

 developed specimen could be recognised by its resemblance to the 

 full-grown fish in shape and appearance, and the younger forms 

 were separated from those of the dab by forming them into 

 series leading up to the oldest. 



It follows from these observations that the }'Oung plaice or 

 larvae after they are hatched sink towards the bottom during 

 their transformation, and that as they reach the perfect condition 

 they make their way towards shallower water and the shore. 



In tracing out or discussing the history and growth of plaice 

 after their transformation from the larval condition it is very 



^ Scientific Transactions of Royal Dublin Society, ser. ii., vol. v., Memoir II. 



